/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.socket;

import java.io.File;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.ServletContext;

import org.apache.catalina.Context;
import org.apache.catalina.connector.Connector;
import org.apache.catalina.startup.Tomcat;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.coyote.http11.Http11NioProtocol;
import org.apache.tomcat.util.descriptor.web.FilterDef;
import org.apache.tomcat.util.descriptor.web.FilterMap;
import org.apache.tomcat.websocket.server.WsContextListener;

import org.springframework.util.Assert;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;

/**
 * Tomcat based {@link WebSocketTestServer}.
 *
 * @author Rossen Stoyanchev
 * @author Sam Brannen
 */
public class TomcatWebSocketTestServer implements WebSocketTestServer {

    private static final Log logger = LogFactory.getLog(TomcatWebSocketTestServer.class);

    private Tomcat tomcatServer;

    private int port;

    private Context context;


    @Override
    public void setup() {
        Connector connector = new Connector(Http11NioProtocol.class.getName());
        connector.setPort(0);

        File baseDir = createTempDir("tomcat");
        String baseDirPath = baseDir.getAbsolutePath();

        this.tomcatServer = new Tomcat();
        this.tomcatServer.setBaseDir(baseDirPath);
        this.tomcatServer.setPort(0);
        this.tomcatServer.getService().addConnector(connector);
        this.tomcatServer.setConnector(connector);
    }

    private File createTempDir(String prefix) {
        try {
            File tempFolder = File.createTempFile(prefix + ".", "." + getPort());
            tempFolder.delete();
            tempFolder.mkdir();
            tempFolder.deleteOnExit();
            return tempFolder;
        } catch (IOException ex) {
            throw new IllegalStateException("Unable to create temp directory", ex);
        }
    }

    @Override
    public void deployConfig(WebApplicationContext wac, Filter... filters) {
        Assert.state(this.port != -1, "setup() was never called.");
        this.context = this.tomcatServer.addContext("", System.getProperty("java.io.tmpdir"));
        this.context.addApplicationListener(WsContextListener.class.getName());
        Tomcat.addServlet(this.context, "dispatcherServlet", new DispatcherServlet(wac)).setAsyncSupported(true);
        this.context.addServletMappingDecoded("/", "dispatcherServlet");
        for (Filter filter : filters) {
            FilterDef filterDef = new FilterDef();
            filterDef.setFilterName(filter.getClass().getName());
            filterDef.setFilter(filter);
            filterDef.setAsyncSupported("true");
            this.context.addFilterDef(filterDef);
            FilterMap filterMap = new FilterMap();
            filterMap.setFilterName(filter.getClass().getName());
            filterMap.addURLPattern("/*");
            filterMap.setDispatcher("REQUEST,FORWARD,INCLUDE,ASYNC");
            this.context.addFilterMap(filterMap);
        }
    }

    @Override
    public void undeployConfig() {
        if (this.context != null) {
            this.context.removeServletMapping("/");
            this.tomcatServer.getHost().removeChild(this.context);
        }
    }

    @Override
    public void start() throws Exception {
        this.tomcatServer.start();
        this.port = this.tomcatServer.getConnector().getLocalPort();
        this.context.addLifecycleListener(event -> {
            if (logger.isDebugEnabled()) {
                logger.debug("Event: " + event.getType());
            }
        });
    }

    @Override
    public void stop() throws Exception {
        this.tomcatServer.stop();
        this.port = 0;
    }

    @Override
    public int getPort() {
        return this.port;
    }

    @Override
    public ServletContext getServletContext() {
        return this.context.getServletContext();
    }

}
